Tension mechanism for the lower threads of sewing-machines.



Patented Apr. 29,1902. A?. G.. BEITZEL.

TENSIUN HEGHANISM FDR THE LOWER VTHREADS 0F SEWING MACHINES.

- (Appucmon mpd' Aug. 15, 1901.)

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UNITED STATES PATENT OFFICE.

GEORG GOT'IWALD BEITZEL, OF COPENHAGEN, DENMARK.

TENSION MECHANISM FOR THE LOWER THREADS OF SEWING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 699,067, dated April29, 1902. Application ledAugust 15, 1901. Serial No. 72,121- (No model.)

T0 tZZ whom t may concern:

Be it known that I, GEORG GoTTwALD BEITZEL, manufacturer, of 23Nrrebrogade, Copenhagen, in the Kingdom of Denmark, have inventedcertain new and useful Improvements in Tightenin g Mechanism for the'Lower Threads ofASewing-Machines; and I do hereby declare the followingto be a full, clear, and exact description of the invention, such aswill enable others skilled in the art to which it appertains to make anduse the same, reference being had to the accompanying drawings, and toletters of reference marked thereon, which form a part of thisspecification.

The present invention refers to a tightening mechanism for the lowerthread of sewing-machines.

The invention is on the accompanying drawings shown in two forms ofconstruction.

Figure l shows the one constructional form in perpendicular section.Fig. 2 is the spoolhouse connected up. Figs. 3 to 5 are details.

a is the spool,upon which the lower thread is wound. The spool is a datone and placed inside a spool-house consisting of two iiat cups b and c.The cup b has a central pin cl fitting into a boring in a pin e on theother cup c, so that .the cups when put on tcp of one another areprevented from moving siderIhe rims of the cups are plane, so that thethread,'which from the spool d, mounted upon the pin e, is passed outbetween the rims, is held fast when the Fcups are pressed together.

The spool-house is placed in the catcher f of the machine, so that oneof the cups bears against a fixed point, while the other cup issubjected to an elastic pressure that forces the rims of the cupstogetherat the same time as lthe aforesaid cup is pressed against theabove mentioned fixed point. However, when the loop of the upper threadis to be slipped around the spool-house by the catcher the pressureofthe spool-house against the fixed point must cease in order that thethread can pass over the spool-house. Arrangements whereby thisisobtained are de scribed in the following:

In the constructional form shown in Fig. 1`

wheels, from a shaft p.

the catcher f rotates on a vertical axis, it being mounted turnablyup'on a hollow perpendicular spindle g, which by means of a setscrew 7iis xed upon a rigid arm t. The catcher is made to rotate, by means ofbevel- On the table of the machine there is placed a plate k. In thehollow spindle g is inserted a rod m, which pressed by a spring n forcesthe spool-house b. cup against the said plate 7a. When the spring npresses upon the lowermost end of the rod m, the rims of the cups'b andc are pressed against each other, and the tightening of the lower threadis thereby obtained. By means of an adj usting-screw-o the spring n canbe made to press more or less against the rod m, and the pressurebetween the rims of the cups canthereby be regulated, so that thetightening of the lower thread may be greater or smaller,as might bedesirable. On

the shaftp is mounted a disk g, having a projection r, and between thedisk q and the spring n is arranged a pin s, capable of sliding in ahole in the arm t. When the projection r strikes against the end .of therod s, this one forces down the spring n, whereby the rod m and the cupsb c are again released.

By pushing aside the plate k the spool-house A may be removed.

Having now particularly described and ascertained the nature ofthe saidinvention and in what manner the same is to be performed, I declare thatwhat I claim is- 1. Anapparatus for tightening the lower thread ofsewing-machines,comprisinga rigid arm provided with a fastening, ahollow spindle detachably secured upon said arm byV means of saidfastening, a catcher revolubly mounted upon said spindle, a rod slidablymounted within said hollow spindle, a revoluble spool-house mounted within said cat-cher and centrally engaged by said rod, and means forintermittingly pressing said rod against said spool-house.

2. An apparatus for tightening the lower thread ofsewing-machines,comprisinga rigid arm provided with a fastening',acatcher revolubly mounted upon said spindle, a rod slidably mountedwithin said hollow spindle, a.v revoluble spool-house mounted withinsaid IQO I "s: utCatcher and centrally engaged by said rod, a

my invention I have signed my namevin presence of two subscribingWitnesses.

GEORG GOTTWALD BEITZEL.

Witnesses:

P. HoFMAN-BANG, J. C. JACoBsEN.

.spring for pressing said rod into engagement .with said spool-house,means controllable at will for adjusting the tension of said spring, andcam mechanism for intermittingly aetuating said spring.

In testimony that. I claim the foregoing as l

